Action for automatic firearms and machine guns



Aug. 3, 1965 R. A. CLOSE 3,198,077

ACTION FOR AUTOMATIC FIREARMS AND MACHINE GUNS Filed March 23, 1964 2 Sheets-Sheet 1 FIG! FIGZ

FIG?) and, a. CZ INVENTOR ACTION FOR AUTOMATIC FIREARMS AND MACHINE GUNS Filed March 23, 1964 R. A CLOSE Aug. 3, 1965 2 Sheets-Sheet 2 mOE m Q. C6044 INVENTOR United States Patent 3,19%,tl77 AQTIQN FUR AUTOMATIQ FEREAEEMS AND MAQHWE GUNS Ross A. Close, 3831 Glenbrook Road, Fairfax County, Va. Filed Mar. 25, 1964, Ser. No. 353,783 1 Claim. ((Cl. 3?--l74) This new action consists of a sleeve b lt for locking the breech block to the receiver. The recoil spring is of the tension type and is placed back of the hammer. The receiver, the sleeve bolt and the guiding sleeve for the breech block can be manufactured from commercially available steel tubing. The above mentioned part lend themselves to manufacturing by the use of automatic screw machines.

Description of drawings:

FIGURE 1 of the drawings shows the new action as it would 'be used in the manufacture of an automatic pistol.

FIGURE 2 shows a side view of the new sleeve bolt and indicates the position of the bolt lugs 6 and cam 11.

FIGURE 3 shows a front view of the new sleeve bolt and indicates the bolt lugs 6.

FIGURE 4 is a longitudinal section of the new action and shows the relative position of the various parts when the action is open.

FIGURE 5 is a side view of the breech block 5 and block lugs 7 with the guiding sleeve 3.

FIGURE 6 is a front end view of the breech block and shows the block lugs 7.

Detailed specifications:

This new automatic action consists of three new parts as follows:

(1) Sleeve bolt.

(2) Two part breech block.

(3) New position and type recoil spring.

All other parts such ar barrel, firing pin, hammer, magazine, etc., are of conventional design.

The receiver shall be made of a cylindrical steel tube, inside threaded at one end to take the barrel. Immediate- 1y back of the barrel thread an acme thread of from four to ten threads per inch shall be cut to receive the sleeve bolt. Cuts shall be made in the receiver to take the magazine, extraction port and locking bolt 4.

The sleeve bolt shall be made of cylindrical steel tube of smaller diameter than the receiver. Acme threads shall be cut inside and outside at one end. The pitch of these acme threads shall be the same pitch as the acme threads in the receiver and the outside threads on the sleeve bolt shall fit the threads on the receiver. The inside acme thread on the sleeve bolt shall be partially removed, leaving the bolt lugs as indicated by 6 on the drawings. 'Ports shall be cut in the sides of the sleeve bolt to allow for the magazine and extraction. A cam 11 shall be cut to receive the locking bolt 4.

The breech block shall be made in two parts. The first part shall consist of the block lugs 7, firing pin and extractor. The second part shall be the guiding sleeve 3 and recoil spring 8.

The first part shall be made from a solid bar of steel. An acme thread that fits the inside thread on the sleeve bolt shall be cut on one end of this bar. Part of the acme thread shall be removed on each side, leaving the block lugs 7. Cuts shall be made for the firing pin, extractor pins, etc. The guiding sleeve shall be made of tubing with slots cut through the wall for the locking bolt, hammer and pins.

The receiver containing the barrel, sleeve bolt, breech block and recoil spring shall be attached to the frame by two rings. One ring 10 encircles the front end of the receiver. The other ring 9 partially encircles the back end of the receiver and shall be fastened to the receiver and recoil spring by the locking bolt 4.

The hammer, trigger, magazine, etc., shall be a part of the frame.

The operation of this new automatic action is as follows:

At the instant of fire the sleeve bolt is held in such a position that lugs 6 and 7 are engaged and lock the breech block 5 to the receiver 1. As the firearm recoils under fire the receiver, barrel, etc., slide back in rings 9 and 10 and the locking bolt 4 turns the sleeve bolt by means of the cam 11. When the receiver has moved about /2 inch the lugs 6 and 7 are no longer in contact, thus releasing the breech block. The breech block moves back, extracting the spent shell, cocking the hammer and causing greater tension in the recoil spring 8. The recoil spring returns the breech block to its original position and in the process loads a new shell from the magazine and turns the sleeve bolt to engage lugs 6 and 7, thus completing the cycle.

I claim:

A firearm comprising in combination a frame having a longitudinally movable cylindrical receiver mounted thereon, a barrel mounted in the cylindrical receiver, a cylindrical sleeve bolt having a cam slot and a cylindrical breech block both mounted'within the cylindrical receiver and longitudinally movable coaxial-1y along the axis of the bore of the barrel, the sleeve bolt being threadedly connected to the receiver, an interrupted screw thread locking the sleeve bolt to the breech block, a locking bolt connecting the frame, the receiver, the sleeve bolt, and the breech block, said locking bolt passing through the cam slot in the sleeve bolt for rotating the sleeve bolt and thus releasing the breech block References Cited by the Examiner UNITED STATES PATENTS 676,995 6/01 Roth et al. 89-l74 1,613,205 1/27 Soncini et al. 89-174 FOREIGN PATENTS 2,105 1915 Great Britain.

BENJAMIN A. BORC'HELT, Primary Examiner. FRED C. MATTERN, 111., Examiner. 

